DALLAS — After all the incredible shots Dirk Nowitzki has hit this postseason, it was his vintage stuff — a straightaway 3-pointer and a pair of free throws — that put the Dallas Mavericks back in the NBA finals.

Nowitzki continued a tremendous roll for him and the Mavs by capping yet another fourth-quarter comeback with a go-ahead 3-pointer with 1:14 left, sending the Mavericks to a 100-96 victory over the Oklahoma City Thunder tonight that closed out the Western Conference finals in five games.

After clawing back from down 15 with 5:04 left in Game 4, the Mavericks were down by six with 4:37 left in this one when they rallied again, outscoring the Thunder 14-4 the rest of the way.

Dallas has never won a championship, and neither has any of its players. Nowitzki and Jason Terry were part of the only Mavericks team to make the finals, in 2006. They were up 2-0 and leading late in Game 3, but lost the series to the Miami Heat in six games.

Dallas could get another crack at the Heat.

LeBron James and Miami lead the Chicago Bulls 3-1 in the Eastern Conference finals. If the Heat win Thursday night, the finals will begin Tuesday in Miami. If the Bulls win Thursday night, the finals will begin next Thursday in the East winner's city.

As fans were starting to clear out, Terry walked down the tunnel carrying the Western Conference championship trophy over his head.

Nowitzki and Shawn Marion each scored 26 points, and were at their best in the fourth quarter. Nowitzki scored nine in the final period, and Marion had 15. J.J. Barea added 14, Terry scored 12 and Jason Kidd had 10 assists and seven rebounds in a victory that set off the biggest on-court celebration in franchise history.

The only other time the Mavs made the finals, they won in Phoenix. This time, the home folks got to enjoy it, including franchise founder Don Carter, who traded his signature white cowboy hat — the one that used to be featured in the team's logo — for a black hat that read "The Finals 2011" with a Mavs logo and the championship trophy. Fans roared again when the overhead video board showed Nowitzki wearing the hat.

Russell Westbrook scored 31 points and seemed to be on a mission to force the series back to Oklahoma City. But he had two crucial turnovers during the furious finish.

Kevin Durant and James Harden finished with 23 points apiece for the Thunder, who bowed out with only their second three-game losing streak of the season.

Considering their youth and the experience gained in this series, Oklahoma City can expect to close in on many more titles. But that was little consolation tonight.

The Mavericks' big edge this series was experience, and it showed in the final two games. Age never slowed them, in part because their legs were refreshed by eight days off before the opener. Winning this game is huge because it earns them at least six days off before the finals.

While Dallas had a deep roster of guys bonded by their lack of a title, getting this far is quite a feat considering second-leading scorer Caron Butler was lost to a knee injury on Jan. 1 and Rodrigue Beaubois, the speedy second-year guard being counted on for a breakout season, hasn't played a minute this postseason.

The Mavericks have done it with defense, anchored by Tyson Chandler, and Nowitzki.

Especially Nowitzki.

He averaged 32.2 points this series, including 11.8 in the fourth quarters. He scored in the 40s twice and was sensational in the Game 4 rally. This wasn't his best performance, but he came through when it mattered most, making that crucial 3 and a pair of free throws with 13.3 seconds left for Dallas' final points.

The Mavericks have long been among the NBA's elite, winning 50 straight games for 11 consecutive seasons. However, it's been a bit hollow because they don't have a title to show for it.

For Kidd and Nowitzki, it would pry them from the group of "best players to never win a ring." At 38, Kidd also would become the oldest point guard ever to guide a team to a title — by several years. Then there's Cuban, Dallas' maverick owner, who could silence many of his critics with a title.

The Mavericks certainly have reason to feel like this is their year.

Since blowing a 23-point lead in the final 14 minutes of Game 4 of a first-round series against Portland, Dallas has won 10 of 11 games. The Mavs joined the 1994 Rockets and 2002 Nets as the only teams to squander at least an 18-point lead going into the fourth quarter of a playoff game, and now all three of those clubs have recovered to reach the finals. The '94 Rockets won the title, the '02 Nets (with Kidd) didn't.